We choose based on project. That being said, we do keep a "library" of plugins (not 80 plugins in length, more like 25ish). These are a few staples, but some plugins' maintenance/upkeep are superior to others so it's good to be flexible and not be married to any.
It definitely makes sense to have an idea of what will help in certain situations, so I don't see this really being a negative thing as long as it is understood there is potentially others out there :)
EDIT: I feel I should also note the agency I work for is very small(6 people). We don't have to maintain standards for that many people, and we have pretty free range on our projects. If there were more than a dozen or so developers, it would be nice to have some kind of standardized solutions so that everyone is familiar with the clients' systems.